1. Field
The present invention relates to a system and a method for adaptively adjusting a battery's charge and discharge rates and limits based upon a known driving route.
2. Description of the Related Art
Most hybrid, plug-in hybrid, and electric vehicles are designed such that the battery charge and/or discharge rates and limits are generally determined based on the power demand from the driver. The limits may be temporarily adjusted, such as during high power demand conditions, and this adjustment may only be allowed for a predetermined period of time to satisfy battery protection requirements. These charge and/or discharge rates and limits may also be set based on each selected operating mode of the vehicle, such as “ECO mode” or “EV mode”. Thus, the running control is based completely on the immediate situation, and any optimization of battery power is calculated using broad generalizations. Accordingly, battery power use is not optimized, as any adjustment of the charge and/or discharge rates and limits may not be adaptively adjusted for specific stretches of driving.
Because of this, vehicles may encounter the following situations. First, a plug-in hybrid vehicle may rapidly deplete its charge at the beginning of a trip in order to avoid having any charge remaining when the trip ends, because the SOC discharge rate is not currently adaptable to specific situations. During sections with high power demand such as highways, the SOC may decrease rapidly and inefficiently, and the vehicle may exit EV mode in a shorter amount of time.
Second, a vehicle may need to accelerate for a short time, such as on an entry ramp on a highway. The vehicle may allow a temporary increase in the discharge rate limit, where the increase amount is set based on a predetermined allowable time to satisfy battery protection requirements. However, since the discharge rate limit is not currently adaptable, the vehicle may, unnecessarily, restrict the battery discharge rate and/or use engine power even though the actual acceleration time may be shorter than the predetermined allowable time.
So, it remains desirable to have a method and a system which allows the battery charge and/or discharge rates and limits to be adjusted, based both on immediate power demand from the driver and the needs of the driver and vehicle to complete the trip with optimal battery power usage. Therefore, if the expected power demand for a known route can be predicted, the charge and/or discharge rates and limits may be adaptively adjusted to allow for increased performance as well as battery power usage optimization.
Thus, there is a need for systems and methods, and/or devices, with adaptive battery charge and discharge rates and limits on a known route.